A glass panel for automotive sun roof systems fitted with a weather strip frame made of elastomeric material and insert molded on a peripheral edge of the glass panel, and a support frame made of metallic material and attached to a lower surface of the glass panel along a peripheral part of the glass panel is well known in the art as disclosed in U.S. Pat. No. 6,099,779. In such an arrangement, it is preferable to avoid the weather strip frame from projecting out of the profile of the roof of the vehicle body, and thereby provide a flush surface. It not only improves the aesthetic quality of the roof panel but also minimizes the aerodynamically induced noises.
The attachment of the weather strip frame to the edge of the glass panel conventionally relied on the bonding force derived from the affinity between the materials of the weather strip frame and glass panel. The weather strip frame typically consists of a weather strip retaining frame which is insert molded onto the peripheral edge of the glass panel, and a weather strip retained by the weather strip retaining frame.
When tilting up/down the glass panel and/or slide opening/closing the glass panel, the outer peripheral part of the weather strip frame inevitably deforms by being dragged on the opposing surface of the roof panel. This deformation tends to pull the weather strip frame away from the edge of the glass panel, and repeated cycles of deformation may eventually cause the weather strip frame to be detached from the glass panel. To avoid this from occurring, it is conceivable to apply a primer to the peripheral part of the glass panel, but it complicates the assembly process, and may create a problem in quality control.